The syntheses and properties of the iodeotrisilanes (IH2Si)2SiH2, (IH2
Si)2SiHI, I3SiSiI2SiH3, (I3Si)2SiH2 and Si3I8 are reported. All trisil
anes were synthesized from the appropriate phenyltrisilanes and hydrog
en iodide, with the exception of I5Si3H3, which was prepared by thermo
lysis of I3SiSiH3. The Si-29-chemical shifts and Si-29Si-29-coupling c
onstants are reported.